Met Office says third UK heatwave will have one big difference

Following last week's unprecedented heatwave, conditions have settled and returned to seasonal norms. However, the Met Office warns this may be temporary, with forecasts suggesting a third heatwave within days.

The UK established a June temperature record of 37.7C on Friday, June 26. The Met Office confirmed this was measured at Lingwood in Norfolk, east of Norwich, surpassing the 37.3C recorded at Santon Downham in Suffolk, establishing a new June temperature record.

Scientists cautioned such extreme heat would have been practically impossible half a century ago, with human-induced climate change driving more severe periods of extreme temperatures. However, the Met Office has indicated one factor will make this third heatwave markedly different.

While temperatures in the 30s remain possible, they are unlikely to match the June record. Crucially, this approaching heatwave will not feature the elevated humidity experienced during last week's hot spell. Last week saw uncommon red heat alerts, hospitals declaring critical incidents, and hosepipe restrictions across parts of England.

The exceptionally high humidity made last week's heatwave feel intolerable, affecting how efficiently bodies regulate temperature. When air holds substantial moisture, sweat evaporates more slowly, making heat loss considerably more difficult. The Met Office reported that last week's air mass travelled across the Atlantic, resulting in significantly higher moisture content.

Higher moisture levels increase dew point temperatures, making it harder for the body to cool itself through sweating. The Met Office has indicated the forthcoming heatwave will be less humid, suggesting conditions will feel considerably more bearable than last week.

Tony Wisson, deputy chief forecaster at the Met Office, explained: "Toward the weekend high pressure will continue to build in across most of the UK as it extends from the Azores. This will lead to more settled warm or very warm conditions for many, especially across England and Wales, though some rain may still affect the far north."

He continued: "The forecast for this weekend suggests that temperatures could approach high 20s C across parts of England, perhaps 30 C in parts of the southeast, with values of mid to high 20s C in Wales."